Fixing element

ABSTRACT

The invention relates to a fixing element for fixing a component to a support part. The element comprises a retaining part ( 1 ) for the component to be fixed and a hollow anchor foot ( 2 ), which is used to anchor the fixing element in a continuous bore of the support part. Two spring arm pairs ( 5, 6 ), which widen towards the retaining part ( 1 ), run from the lower edge in opposing openings ( 4 ) in the wall of the anchor foot ( 2 ), one short and one long spring arm ( 5  and  6 ) respectively lying adjacent to one another in one of the openings ( 4 ) and being offset in relation to the short and long spring arm ( 5  and  6 ) in the other opening ( 4 ). As both spring arm pairs ( 5, 6 ) are graduated towards the retaining part ( 1 ), starting from a respective outer edge ( 11, 12 ) that lies at the greatest radial distance from the central axis (M) of the fixing element, front faces ( 7, 8 ) and step faces ( 9, 10 ) are created on different horizontal planes. The faces can rest on the underside of a support part. Vertical bearing faces are created simultaneously ( 13, 14 ) at different radial distances from the central axis (M). The vertical faces can rest on the peripheral face of bores of varying diameters. The fixing element can thus be used both for a wide range of material strengths of the support part and for a wide range of diameters of the bore with high functional reliability. Both ranges can be covered by small graduation increments. An umbrella-shaped, spring stop ( 15 ) lying between the retaining part ( 1 ) and the anchor foot ( 2 ) permits a continuous adaptation between the stages for the range of material strengths.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No.PCT/EP03/10364, filed on Sep. 18, 2003, which claims priority to GermanPatent Application No. 102 45 276.8, filed on Sep. 27, 2002. Thedisclosures of the above applications are incorporated herein byreference.

BACKGROUND OF THE INVENTION

The invention pertains to a fixing element for fixing a component on asupport part, wherein the fixing element comprises a retaining part forthe component to be fixed, a hollow anchor foot for anchoring the fixingelement in a continuous bore of the support part, and a spring stop thatis arranged between the retaining part and the anchor foot, wherein thewall of the anchor foot contains two opposite openings, wherein twospring arms that are spread apart in the direction of the retaining partrespectively originate at the lower edges of the openings, wherein theends of the spring arms have faces that adjoin the underside of thefixing element after it is inserted into the bore of a support part, andwherein the faces of two diagonally opposing spring arm pairs lie in twodifferent horizontal planes.

Fixing elements of this type are generally known, but are primarilysuitable for being fixed in a bore of the support part that has acertain diameter and for a certain material thickness of the supportpart. This means that specially adapted fixing elements must berespectively manufactured for bores with different diameters and forsupport parts with different material thicknesses.

DE 201 01 328 U1 discloses a fixing element in which tolerancecompensation between the fixing points can be achieved when mounting oneplanar body on another with the aid of several such fixing elements.This is achieved by realizing the fixing element in two parts and byallowing a certain mobility of the anchor foot in the retaining partperpendicular to the center axis. The anchor foot is prevented fromturning in the retaining part by lateral projections on the shaft.Although not required, the outside surfaces of the spring arms may bedivided into two sections by a shoulder such that one planar body canassume an intermediate or pre-assembly position relative to other planarbody during the installation, wherein the connection is still loose andone body can still be laterally moved in the aforementioned intermediateor pre-assembly position. This is realized by making the diameterdefined by the outside surfaces of the spring arms smaller behind theaforementioned shoulder than the diameter of the bore in the body, intowhich the anchor foot is inserted. The actual fixing of the componenttakes place in a second step, when a shoulder on the free end of thespring arms engages behind the edge of the bore.

DE 2 153 062 A1 discloses a fixing element in which the free ends of thespread-apart spring arms are concavely bent at the location at whichthey should come in contact with the edge of the bore in the supportpart. This allegedly serves to anchor the same fixing element in boreswith diameters that vary over a certain range. However, a secure andrigid anchoring cannot be achieved with the curved contact surface ofthe spring arms; another reason for this is that this publication doesnot aim to realize anchoring in bores with different diameters of acertain size, but rather with diameters that vary over a certain range.Pairs of laterally and perpendicularly extending projections on theshaft are only able to prevent a horizontal displacement of the anchorfoot in a bore with a certain diameter, i.e., in a bore of only onesize. The fixing element could not even be installed in a bore with asmaller diameter, and the installation in a bore of larger diametercould lead to the spring arms disengaging due to the lateral play of theanchor foot.

U.S. Pat. No. 2,424,757 discloses a fixing element for fixing acylindrical component on a plate-shaped support part. The fixing elementconsists of a sleeve that is pushed onto the cylindrical component andfrom which a pair of spread-apart spring arms protrudes laterally. Thefree ends of these spring arms contain several steps. This is intendedto allow the anchoring in support parts with different thicknesses. Therisk that the spring arms will disengage is also not eliminated in thiscase such that the component practically cannot be securely fixed in thebore of a support part.

DE 43 07 434 A1 and corresponding publication EP 0 615 071 B1respectively disclose a holding element that contains an anchor foot inthe form of a base body of rectangular cross section. All four lateralsurfaces of this base body are provided with snap-in tabs thatrespectively lie diagonally opposite one another and can be snapped intorecesses in the lateral surfaces of the base body. Two opposing snap-intabs are realized in T-shaped form and have faces that point to theretaining part on the T-crosspieces. This allegedly results in acentering cage effect and consequently a secure retention in the bore ofa support part, even if the retaining part turns about its longitudinalaxis in the bore. The faces of the snap-in tabs provided may all lie inthe same horizontal plane. Alternatively, pairs of snap-in tabs may alsolie in different horizontal planes such that the retaining part can beutilized on support parts of different thicknesses.

DE-GM 81 13 637 discloses a holding element that, in theory, also allowsthe utilization on support parts with different material thicknesses.According to one of the embodiments described in this publication, twopairs of elastic tabs that are directed toward the retaining part areprovided on a base body that forms the anchor foot of round crosssection, wherein the faces of the elastic tab pairs may also lie indifferent horizontal planes pair-by-pair. In this case, the firstelastic tabs of both elastic tab pairs lie directly adjacent to oneanother on the circumference of the base body analogous to the otherelastic tabs of the elastic tab pairs, i.e., in such a way that theelastic tabs of the shorter elastic pair lie directly opposite of theelastic tabs of the longer elastic pair, i.e., the respective elastictabs are diagonally offset relative to one another. This is intended toallow a secure retention here in support parts with, specifically, twodifferent material thicknesses. In order to utilize the holding elementon support parts with more than two material thicknesses, additionalelastic tab pairs with faces may be provided on the circumference of thebase body in correspondingly different horizontal planes.

Known holding or fixing elements are designed for use in bores withdifferent diameters in support parts or on support parts of differentthicknesses or material thicknesses, the design of these holding orfixing elements is often relatively complicated and their manufacture iscorrespondingly costly. Nonetheless, a secure and rigid connection stillcannot be ensured in all cases.

SUMMARY OF THE INVENTION

The invention is based on the objective of developing a fixing elementof the initially mentioned type, in which the anchor foot is realized insuch a way that it can be used on support parts with bores of differentdiameters as well as on support parts with different materialthicknesses, while still ensuring a secure and rigid anchoring and, inparticular, preventing the spring arms from disengaging when the fixingelement is laterally loaded. The new fixing element should not only besuitable for use in bores with certain different diameters and onsupport parts with certain different thicknesses, but rather over an atleast approximately continuous diameter range and an at leastapproximately continuous material thickness range.

According to the invention, this objective is realized in that the shortspring arms as well as the long spring arms radially widen in thedirection of the retaining part, namely from the lower edge of therespective opening to an outer edge of the short spring arms and anouter edge of the long spring arms, and are then radially recessed up totheir respective face in the form of several steps such that severalhorizontal step surfaces are formed in different planes and severalvertical contact surfaces are formed at different radial distances fromthe center axis M of the fixing element on each spring arm, wherein thefaces or the individual horizontal step surfaces of one spring arm pairlie in the same respective planes and its individual vertical contactsurfaces lie at the same respective radial distances from the centeraxis M, but in different planes and at different radial distances fromthe center axis M relative to the other spring arm pair.

This makes it possible to utilize a single fixing element for differenthole or bore diameters in the support part and for different materialthicknesses of the support part. A broad range of different borediameters and material thicknesses can be respectively covered in verysmall increments due to the faces or step surfaces that lie in offsethorizontal planes and the vertical contact surfaces that lie at offsetradial distances from the center axis M.

It is advantageous that the longest radial distance between an outeredge of one spring arm and the center axis of the fixing element islonger than half the diameter of the largest bore in the support part bysuch an amount that the anchor foot cannot be disengaged if the fixingelement is laterally loaded, and that the shortest possible radialdistance between the root of the spring arms and the center axis isslightly shorter than half the diameter of the smallest bore in thesupport part. This also makes it possible easily to insert the anchorfoot of the fixing element into the smallest bore provided.

The steps on the short spring arms and the steps on the long spring armsare preferably offset relative to one another in such a way that thefaces or horizontal step surfaces of the long spring arms and the facesor horizontal step surfaces of the short spring arms are alternatelybrought into contact with the underside of the support part as thematerial thickness of the support part increases and the verticalcontact surfaces of the short spring arms and the vertical contactsurfaces of the long spring arms accordingly are alternately broughtinto contact with the circumferential surface of a bore as the borediameter increases. The diametral range of the bores and the materialthickness range of the support part can be covered in particularly smallincrements due to these horizontal faces or step surfaces and verticalcontact surfaces that are alternately offset on the two spring armpairs. With respect to the material thickness range, the adaptationbetween the increments is realized continuously because the stopelastically comes into contact with the upper side of the support part.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in greater detail below by way of an examplewith reference to the enclosed drawing; it shows:

FIG. 1, a perspective representation of an embodiment of the fixingelement according to the invention;

FIG. 2, a side view of the fixing element according to FIG. 1 inconnection with the covered material thickness range F;

FIG. 3, the side view according to FIG. 2 in connection with the coveredbore diameter range;

FIG. 4, a side view of the fixing element that is turned by 90° relativeto FIG. 3, namely in connection with the covered bore diameter range,and

FIG. 5, a scaled-down cross section through the anchor foot above theshorter spring arm pair in FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-3 show different views of a fixing element with a retaining part1 for the component to be fixed on the preferably plate-shaped supportpart that is not illustrated in the figures, e.g., a mounting plate, andan anchor foot 2 that is rigidly connected to the retaining part 1 andserves for rigidly anchoring the fixing element in a continuous bore ofthe support part. The present invention essentially pertains to thedesign of this anchor foot 2. The anchor foot 2 has the form of a hollowcylinder, the wall of which conventionally is slightly beveled 3 on itsfree end in order to simplify the insertion of the anchor foot 2 intothe bore of the support part. The cylindrical wall of the anchor foot 2is provided with two opposing openings 4 that extend as far as theretaining part 1. Two spring arms 5, 6 lie adjacent to one another andprotrude from the lower edge of each opening 4, wherein the spring armsare spread apart in pairs in the direction of the retaining part 1. Thespring arm pair 5 is shorter than the spring arm pair 6. The arrangementis chosen such that the shorter spring arm 5 on one opening 4 liesdirectly opposite the longer spring arm 6 on the other opening 4 andvice versa (in this respect, see also FIG. 5). Thus, the spring armpairs 5 and 6 have faces 7 and 8 that lie in different horizontalplanes. When the anchor foot 2 is inserted into a bore provided in thesupport part for this purpose, the faces 7 or 8 of one or the otherspring arm pair 5, 6 come in contact with the underside of the supportpart as a function of the material thickness of the support part. Inorder to allow the anchoring of the fixing part according to theinvention in support parts with more than two given material thicknessesand to make it possible to cover an entire range of materialthicknesses, the spring arms 5, 6 contain several (in the embodimentshown, two) steps from their respective face 7, 8 to their respectiveouter edge 11, 12. These steps respectively comprise horizontal stepsurfaces 9, 10 (in this respect, see also FIG. 2) that are directedtoward the retaining part. The step surfaces 9, 10 of one spring armpair 5, 6 lie in the same planes respectively, but in different planesrelative to the other spring arm pair 6, 5. In the embodiment shown, thefaces 7, 8 and the step surfaces 9, 10 of the spring arm pairs 5, 6consequently form contact surfaces for the underside of a support partin six different planes in small increments. A broad range of materialthicknesses of the support part can thereby be covered in very smallincrements. A continuous adaptation to the values of the materialthickness is achieved between the increments due to the effect of theumbrella-shaped stop 15 that is arranged between the retaining part 1and the anchor foot 2 and comes in elastic contact with the upper sideof the support part. In one specific instance, this was realized for amaterial thickness range between F1=0.6 mm and F2=3.0 mm (see FIG. 2).

As mentioned above, the spring arms 5, 6 are spread apart in thedirection of the retaining part 1, as far as the outer edge 11, 12 ofthe respectively lowest step surface 9, 10 that defines the longestradial distance R1 from the center axis M of the fixing element (seeFIGS. 3 and 4). In addition to the horizontal step surfaces 9, 10, thesteps on the spring arms 5, 6 also comprise vertical contact surfaces13, 14, the radial distance of which decreases from the center axis M onthe ensuing steps that ascend in this direction. When the fixing elementis inserted, the vertical contact surfaces 13, 14 come in contact withthe circumferential surface of the bore. If the bore has a smalldiameter, the spring arms 5, 6 move into the anchor foot 2 through theopenings 4 until the appropriate contact surface is reached. This offsetarrangement of the short and long spring arms 5, 6 also makes itpossible for these spring arms to carry out such a movement withoutimpairing one another during the insertion into a narrow bore. Thespring arms 5, 6 are able to cover a broad bore diameter range due tothe different radial distances of the contact surfaces from the centeraxis M; the shortest radial distance R2 possible corresponds to thediameter of the anchor foot 2 (see FIG. 4). In one specific example,this was realized for a bore diameter range between D1=6.2 mm and D2=7.2mm.

The longest radial distance R1 from the center axis M, i.e., that of theouter edges 11, 12 of the spring arms 5, 6, is chosen such that 2×R1 isgreater than the largest bore diameter D1 in order to prevent the anchorfoot 2 from disengaging when the fixing element is laterally loaded. Theshortest radial distance R2, i.e., the diameter of the anchor foot 2, issuch that 2×R2 is slightly smaller than the smallest bore diameter D2 sothat the fixing element can be mounted without problem.

The described fixing element consequently can be utilized in afunctionally reliable fashion over a broad bore diameter range and overa broad material thickness range of the support part. If the steps onthe spring arms 5, 6 are offset in such a way that the step surfaces 9,10 of both spring arm pairs 5, 6 alternately come in contact with theunderside of support parts of different material thicknesses and thecontact surfaces 13, 14 of both spring arm pairs 5, 6 alternately comein contact with the circumferential surface of bores with differentdiameters, both ranges can be covered almost continuously in very smallincrements. With respect to the range of material thicknesses, acontinuous adaptation between the increments is achieved with the aid ofthe umbrella-shaped stop 15 that comes in elastic contact with the upperside of the support part.

The foregoing discussion discloses and describes an exemplary embodimentof the present invention. One skilled in the art will readily recognizefrom such discussion, and from the accompanying drawings and claims thatvarious changes, modifications and variations can be made thereinwithout departing from the true spirit and fair scope of the inventionas defined by the following claims.

1. A fixing element for fixing a component on a support part, whereinsaid fixing element comprises: a retaining part for the component to befixed, a hollow anchor foot for anchoring the fixing element in acontinuous bore of the support part, and a spring stop that is arrangedbetween the retaining part and the anchor foot, wherein a wall of theanchor foot contains two opposing openings, wherein two spring arm pairsthat are spread apart in a direction of the retaining part respectivelyoriginate at a lower edge of said openings, wherein the spring arms havefaces that adjoin the fixing element after it is inserted into the boreof the support part, and wherein the faces of two diagonally opposingspring arms lie in two different horizontal planes, characterized by thefact that the short spring arms (5) as well as the long spring arms (6)radially widen in the direction of the retaining part (1), from a loweredge of the respective opening (4) to an outer edge (11) of the shortspring arms (5) and an outer edge (12) of the long spring arms (6), andare then radially recessed up to their respective face (7, 8) in a formof several steps such that several horizontal step surfaces (9, 10) areformed in different planes and several vertical contact surfaces (13,14)are formed at different radial distances from a center axis (M) of thefixing element on each spring arm (5,6), wherein the faces (7,8) and theindividual horizontal step surfaces (9,10) of one spring arm pair (5,6)lie in similar respective planes and its corresponding individualvertical contact surfaces (13,14) lie at similar respective radialdistances from the center axis (M), but in different planes and atdifferent radial distances from the center axis (M) relative to anotherspring arm pair (6,5).
 2. The fixing element according to claim 1,characterized by the fact that at least one radial distance (R1) betweenan outer edge (11, 12) of one spring arm (5,6) and the center axis (M)of the fixing element is longer than half a diameter (D½) of the bore inthe support part by such an amount that the anchor foot (2) is securedtherein, and by the fact that the shortest possible radial distance (R2)between the base of the spring arms (5,6) and the center axis (M) isslightly less than half the diameter (D 2/2) of the bore in the supportpart.
 3. The fixing element according to claim 1, characterized by thefact that the horizontal step on the short spring arms (5) and thehorizontal step on the long spring arms (6) are offset relative to oneanother in such a way that the faces (8) or horizontal step surfaces(10) of the long spring arms (6) and the faces (7) or horizontal stepsurfaces (9) of the short spring arms (5) are alternately brought intocontact with an underside of the support part as a material thicknessthereof increases and the vertical contact surfaces (13) of the shortspring arms (5) and the vertical contact surfaces (14) of the longspring arms (6) accordingly are alternately brought in contact with acircumferential surface of the bore as the diameter thereof increases(D2 to D1).
 4. A fixing element for fixing a component on a supportpart, comprising: a retaining part, a spring stop coupled to saidretaining part, and an anchor foot coupled to said spring stop, saidanchor foot comprising a plurality of spring arms, said plurality ofspring arms comprising at least one short spring arm and at least onelong spring arm, wherein each of said plurality of spring arms is:biased to extend from an outer surface of said anchor foot, capable ofbeing compressed, and radially recessed such that a plurality ofsubstantially horizontal surfaces are formed in a plurality of differentplanes and a plurality of substantially vertical contact surfaces areformed at a plurality of different radial distances from a center axisof said fixing element.
 5. The fixing element of claim 4, wherein saidplurality of spring arms comprises at least one pair of short springarms and at least one pair of long spring arms.
 6. The fixing element ofclaim 5, wherein each of said plurality of substantially horizontalsurfaces formed on a first short spring arm of said at least one pair ofshort spring arms lies in a substantially similar plane to one of saidplurality of substantially horizontal surfaces formed on a second shortspring arm of said at least one pair of short spring arms.
 7. The fixingelement of claim 6, wherein each of said plurality of substantiallyvertical contact surfaces formed on said first short spring arm lies ata first radial distance from said center axis of said fixing elementapproximately equal to a second radial distance from said center axis ofsaid fixing element corresponding to one of said plurality ofsubstantially vertical contact surfaces formed on said second shortspring arm.
 8. The fixing element of claim 6, wherein each of saidplurality of substantially horizontal surfaces formed on a first longspring arm of said at least one pair of long spring arms lies in asubstantially similar plane to one of said plurality of substantiallyhorizontal surfaces formed on a second long spring arm of said at leastone pair of long spring arms.
 9. The fixing element of claim 6, whereineach of said plurality of substantially vertical contact surfaces formedon a first long spring arm of said at least one pair of long spring armslies at a first radial distance from said center axis of said fixingelement approximately equal to a second radial distance from said centeraxis of said fixing element corresponding to one of said plurality ofsubstantially vertical contact surfaces formed on a second long springarm of said at least one pair of long spring arms.
 10. The fixingelement of claim 5, wherein each of said plurality of substantiallyhorizontal surfaces formed on a first long spring arm of said at leastone pair of long spring arms lies in a substantially similar plane toone of said plurality of substantially horizontal surfaces formed on asecond long spring arm of said at least one pair of long spring arms.11. The fixing element of claim 10, wherein each of said plurality ofsubstantially vertical contact surfaces formed on said first long springarm lies at a first radial distance from said center axis of said fixingelement approximately equal to a second radial distance from said centeraxis of said fixing element corresponding to one of said plurality ofsubstantially vertical contact surfaces formed on said second longspring arm of said at least one pair of long spring arms.
 12. The fixingelement of claim 4, wherein said spring stop and said plurality ofspring arms are capable of cooperating such that said fixing element issecured to said support part.
 13. The fixing element of claim 4, whereinsaid anchor foot further comprises a plurality of openings.
 14. Thefixing element of claim 13, wherein said plurality of spring arms arecoupled to said openings.
 15. A fixing element for fixing a component ona support part, comprising: a retaining part, a spring stop coupled tosaid retaining part, and an anchor foot coupled to said spring stop,said anchor foot comprising a plurality of spring arms, said pluralityof spring arms comprising at least one pair of short spring arms and atleast one pair of long spring arms, wherein each of said plurality ofspring arms is: biased to extend from an outer surface of said anchorfoot, capable of being compressed, and radially recessed such that aplurality of substantially horizontal surfaces are formed in a pluralityof different planes and a plurality of substantially vertical contactsurfaces are formed at a plurality of different radial distances from acenter axis of said fixing element, and further wherein: said springstop and said plurality of spring arms are capable of cooperating suchthat said fixing element is secured to said support part, said pluralityof spring arms comprises at least one pair of short spring arms and atleast one pair of long spring arms, each of said plurality ofsubstantially vertical contact surfaces formed on a first long springarm of said at least one pair of long spring arms lies at a first radialdistance from a center axis of said fixing element approximately equalto a second radial distance from said center axis of said fixing elementcorresponding to one of said plurality of substantially vertical contactsurfaces formed on a second long spring arm of said at least one pair oflong spring arms, each of said plurality of substantially horizontalsurfaces formed on said first long spring arm lies in a substantiallysimilar plane to one of said plurality of substantially horizontalsurfaces formed on said second long spring arm, said anchor foot furthercomprises a plurality of openings, and said plurality of spring arms arecoupled to said openings.
 16. The fixing element of claim 15, whereineach of said plurality of substantially vertical contact surfaces formedon a first short spring arm of said at least one pair of short springarms lies at a third radial distance from said center axis of saidfixing element approximately equal to a fourth radial distance from saidcenter axis of said fixing element corresponding to one of saidplurality of substantially vertical contact surfaces formed on a secondlong spring arm of said at least one pair of long spring arms.
 17. Thefixing element of claim 16, wherein each of said plurality ofsubstantially horizontal surfaces formed on said first short spring armlies in a substantially similar plane to one of said plurality ofsubstantially horizontal surfaces formed on said second short springarm.
 18. The fixing element of claim 15, wherein each of said pluralityof substantially horizontal surfaces formed on a first short spring armof said at least one pair of short spring arms lies in a substantiallysimilar respective plane to one of said plurality of substantiallyhorizontal surfaces formed on a second short spring arm of said at leastone pair of short spring arms.